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Re: (ITS#7570) fix MDB_GET_MULTIPLE and MDB_NEXT_MULTIPLE behaviour

hyc@symas.com wrote:
> claude.brisson@gmail.com wrote:
>> Full_Name: Claude Brisson
>> Version: HEAD
>> OS: linux 64
>> URL: ftp://ftp.openldap.org/incoming/0001-fix-MDB_GET_MULTIPLE-and-MDB_NEXT_MULTIPLE.patch
>> Submission from: (NULL) (84.103.74.130)
>>
>>
>> In a db with MDB_DUPSORT flag, when there is only one DUP data for a key,
>> F_DUPDATA is not set for this key, and there is no sub-cursor.
>>
>> In this case, the current behaviour of MDB_GET_MULTIPLE and MDB_NEXT_MULTIPLE is
>> broken because they make the assumption that there is always a sub-cursor for
>> DUP data, which is only true for keys with more than one DUP data.
>>
>> This patch address this specific issue.
>
> Something's wrong with this patch, it breaks MDB_GET_MULTIPLE/NEXT_MULTIPLE
> usage in slapd. Need to investigate further.
>
The original code is correct. GET_MULTIPLE/NEXT_MULTIPLE are only valid when 
there actually are duplicate records. MDB_NEXT_MULTIPLE is essentially just a 
shortcut for calling MDB_NEXT_DUP in a loop. If there are no dups, then 
MDB_NEXT_DUP (and MDB_NEXT_MULTIPLE) return MDB_NOTFOUND.

This patch was in mdb.master but has now been reverted. Closing this ITS.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/